initial population-based PC/AS preassessment is essential if the approach is to be efficient and timely. The population-based preassessment would provide guidance concerning the extent of the problem and identify locations and population groups in which compensation would be viable. Estimated radiation doses to organs other than thyroid and the corresponding PC/AS values for the tissues at risk are substantially lower than those for the thyroid. Because of the low radiation doses estimated for organs other than the thyroid, the committee suggests that the preassessment would enable the implementing agency to focus on selected diseases, areas and population groups. The results of the preassessment, however, would depend greatly on the PC/AS criterion for compensation that is eventually adopted.

We presented an example showing the importance of the PC/AS criterion, especially the influence of the percentile of the PC/AS distribution that is specified for awarding compensation. If Congress chooses a 95th or 99th percentile, compensation would be awarded for very low values of estimated